Yarn twisting apparatus

ABSTRACT

A yarn twisting apparatus comprises a spindle which holds and rotates a bobbin for winding a yarn, an annular ring encircling the spindle, a ring holder movable with relative reciprocating motion axially of the spindle, having fluid nozzles and supporting the ring. A magnetic force is applied between the ring and the ring holder. The ring is supported and stabilized without coming into contact with the ring holder by the repulsive force of the fluid jetting out from the fluid nozzles and by the attractive magnetic force.

o I llnited States Patent 11 1 1111 3,851,448 Sano et a1. Dec. 3, 1974 [54] YARN TWISTING APPARATUS 2,932,152 4/1960 Jackson 57 124 x 3,122,876 3/1964 Matsui..... 57/124 [751 lnvemmsl Taka" Katuhm Fukwa, 3,324,643 6/1967 101ml 57/124 2 of g g i 3,494,120 2/1970 Chilpan et a1. 57/75 ouzou ameno, igaen, a 0 Japan [73] Assignee: Tory Industries, Inc., Tokyo, Japan Primary ExammeFJOhn Petrakes [22] Filed: July 18, 1973 21 Appl. No.: 380,211 57 ABSTRACT A arn twistin a aratus com rises a s indle which 30 F A p y 8 PP P P 1 orelgn pphcatmn nonty Data holds and rotates a bobbin for winding a yarn, an an- Aug. 19, 1972 Japan 47-83095 nular g encircling the p a g holder able with relative reciprocating motion axially of the [52] US. Cl 57/75, 57/101, 5577/1122; Spindle, having fluid nozzles and Supporting thg ring 1 1 Cl D 0 1h A magnetic force is applied between the ring and the g 'P i 124 ring holder. The ring is supported and stabilized with- 1 0 mm 1 2 out coming into contact with the ring holder by the repulsive force of the fluid jetting out from the fluid 56 1 References Cited nozzles and by the attractive magnetic force.

UNITED STATES PATENTS 31 Claims, 40 Drawing Figures 2,796,726 6/1957 Klein 57/124 X PAIENIEM 319M sum 1 or 7 REPULSION BY A FLUID E C R O F m T E N M P m TI 5 F O T m O P GAP BETWEEN RING AND RING HOLDER W PAIEIIIEIIIEI 3W 3.851.448

I SHEET 3 or 7 -LEGEND- NON-MAGNETIC SUBSTANCE (d) I I I I l I I i I I I I I I I I I I I I I I I I PATENTED LEE 31 914 lUJO/b/ v I PATENTEU EEC 31974 SHEET 5 OF 7 {a} Fig 12m) Pi .I5

, 11 AEEB ZOCUMEE J x 2 mkzxlmzou ozEQm W w w 0 NOT USING MAGNET USING MAGNET T ZOCOMEE 4394i Z wPZ PmZOU @Z mn m PRESSURE OF AIR .JET (Kg/cm PATENMQEQ BISM SHEET 8 BF 7 YARN TWISTING APPARATUS BACKGROUND OF THE INVENTION The present invention relates to an improvement in a yarn twisting apparatus. More in particular, the present invention relates to a yarn twisting apparatus in which yarn is twisted by use of an annular ring supported while floating in space without coming into contact with any associated ring holder. The yarn is wound around a bobbin.

Yarn twisting apparatus in which a ring is supported in a floating condition without coming into contact with a ring holder has been reported heretofore in U.S. Pat. No. 2,932,152, and in many other publications.

However, it has been very difficult for such apparatus actually to support a-ring stably in a floating condition, and this has not been realized in practice yet. For example, the apparatus disclosed in U.S. Pat. No. 2,932,152 attempts to float a ring by magnetic repulsion and, at the same time, to stabilize the ring in a transverse direction by means of compressed air. How ever, when the ring is displaced out from a balanced position, a strongly unbalanced magnetic force is exerted radially of the ring, making the ring unstable. In order to stabilize the ring radially, air is jetted transversely to balance the magnetic force. However, it is actually very difficult to support the ring with good stability without causing contact with the ring holder. Accordingly, it issubstantially impossible from an engineering point of view to make-such an apparatus practical.

Accordingly, an object of the present invention is to provide a yarn twisting apparatus capable of supporting a ring in a floating condition without coming into Contact with the ring holder.

Another object of the present invention is to provide a yarntwisting apparatus capable of supporting a ring very stably in a floating condition without contact with the ring holder. l

A further object of the present invention is to provide a yarn twisting apparatus supporting a ring in a floating condition by balancingthe forces of a compressed fluid and of magnetism.

Other objects will become apparent hereinafter.

SUMMARY OF THE INVENTION According to. this invention a yarn twisting apparatus is provided which is capable of supporting-a ring in a stable condition without causing contact with a ring holder by simultaneously applying forces of repulsion generated by a fluid jet, and attractive forces generated by magnetism, concurrently to said ring.

The apparatus according to this invention includes:

d. means for generating a magnetic force by which said ring is attracted to said ring holder.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a set of two curves showing the relation between the gap between ring and ring holder to the load capacity (absolute volume), one curve for attractive magnetic force and the other for repulsion of air.

FIG. 2 is a drawing explaining Roters formula concerning the magnetic lines of force of magnets mutually attracting and transferring in a rectangular direction.

FIGS. 3(a) and (b) show one embodiment of the present invention. FIG. 3(a) is a cross-sectional view of a ring and a ring holder. FIG. 3(b) is a plan view of a part of the ring holder. A section taken along the line X X in FIG. 3(b) is the left-hand half of FIG. 3(a), while a section taken along the line Y Y in FIG. 3(b) is the right-hand half of FIG. 3(a).

FIGS. 4(a) and (b) represent another embodiment of the present invention. FIG. 4(a) is a cross-sectional view of a ring and a ring holder. FIG. 4(b) is a plan view of part of the ring holder.

FIGS. 5(a) (d) show still another embodiment of the present invention. FIG. 5(a) is a sketch showing the structure of a magnet. FIG. 5(b) is a sectional view taken along the line X X in FIG. 5(d). FIG. 5(c) is a view in section taken along the line Y Y in FIG. 5(d). FIG. 5(d) is a plan view of the ring holder.

FIGS. 6(a) (0) show still another embodiment of the present invention. FIG. 6(a) is a sketch showing the structure of a magnet. FIG. 6(b) is a view in section taken along a line X X in FIG. 6(c) of a ring and a ring holder. FIG. 6(0) is a plan view of the ring holder.

FIG. 7 shows still another embodiment of the present invention, being a cross-sectional view of a ring and a ring holder.

FIG. 8 is a schematic view showing combinations of dispositions of magnets used in the present invention.

FIG. 9 is a schematic view showing a preferred disposition of magnets used in the embodiments of FIG. 3 and FIG. 4.

FIGS. 10(a) (e) are sketches showing magnet constructions useful in the situation when the ring rotates.

FIG. 11 is a perspective view of a ring holder provided with a slit for guiding the yarn.

FIGS. 12 (a) and (b) are fragmentary perspective views showing annular electromagnets in the situation where a slit is provided on a ring holder.

FIG. 13 is a schematic view showing principles of stabilization of rings in FIG. 3, FIG. 4, FIG. 5 and FIG. 6, respectively.

FIG. 14' is a perspective view showing an embodiment having an annular permanent magnet and a plurality of steps in a magnetic pole.

FIG. 15 is a cross-sectional view of a ring and a ring holder when air is also propelled as a jet from the side wall of said holder.

FIG. 16 is a graph of pneumatic pressure spring constants, illustrating properties of the magnet of the present invention.

FIG. 17 shows still another embodiment of the present invention. being a cross-sectional view of a ring and a ring holder surrounding a yarn package.

FIG. 18 is a perspective view showing magnetic action in the embodiment shown in FIG. 17.

FIG. 19 is a schematic view illustrating the stability of the ring and the embodiment of FIG. 17.

FIGS. 20(a) (c) and FIGS. 21(a) and (b) are fragmentary views giving examples of the structures of electromagnets where a slit is provided on the ring holder; FIGS. 20(a) and 21(a) are perspective views and FIGS. 20(b), 20(c) and 21(b) are cross-sectional VIeWS.

FIG. 22 is a perspective view showing an example of the structures of ring and ring holder where the ring is stationary in the embodiment shown in FIG. 17.

FIG. 23 is a cross-sectional view showing still another example of the ring and ring holder structure.

FIG. 24 is a cross-sectional view showing an embodiment of the invention in which a hook is provided on the ring, and

FIG. 25 is a cross-sectional view showing an embodiment in which another pneumatic nozzle is provided in the apparatus of FIG. 17.

DETAILED DESCRIPTION OF THE INVENTION The yarn twisting apparatus of the present invention embodies a yarn guide which surrounds the package upon which the yarn is being wound combined with a ring support which is maintained in spaced-apart relation to the yarn guide, so that the yarn guide is in a free floating condition as it reciprocates axially along the package.

The support includes an air chamber and ports for emitting a pressurized jet of fluid, such as compressed air for example. Also, a magnet is provided to apply an attractive magnetic force between the guide and the support to obtain noncontacting and stable support for the guide by combined repulsion and attraction.

As a result of strenuous studies, we have found that when a repulsive pneumatic force is applied between a ring support and a ring, an attractive magnetic force is simultaneously effected between them in an opposite direction. the repulsive force is balanced by the attractive force. and it becomes possible to create a condition of stability under which substantially no resultant force is effective upon the ring. At the same time, displacement of the ring toward the ring support in a direction perpendicular to the attractive magnetic force is limited, and stability of the ring is greatly improved. Hereinbelow, the present invention will be explained in detail by reference to embodiments and schematic views shown in the drawings.

FIG. 1 is a graph showing the relation between (a) the repulsion created by a fluid jet used in the present invention and (b) the attractive magnetic force, in which the gap between the ring and the ring holder is plotted as the abscissa and the absolute value of load capacity is plotted as the ordinate. As is shown in FIG. 1, when gradients of curves of load capacity of the respective magnetic and pneumatic forces are established, the point of intersection of the two curves becomes a point of stability at which the resultant force is zero, because repulsion and attraction are opposed in direction.

Next, referring to FIG. 2, an explanation will be made concerning the attractive magnetic force of a magnet and its effect in a perpendicular direction. In FIG. 2 magnetic flux density values of mutually attractive magnets l, l are assumed to be constant (except for a non-uniform portion of terminal leakage) and to have a perrneance P. In this case, when the magnet 1 is displaced through a differential increment dr in a direction r which is perpendicular to the magnetic lines of force of the magnet, a restoring force comes into effect. This restoring force Fr is as follows, according to Roters formula:

Fr (1 (magnetomotive force) dP/dr wherein P is approximately equal to the product obtained by dividing the area S that is common to the two magnetic poles, by the gap 6 between them.

Accordingly, P S/e and Fr a (magnetomotive force) dS/dr 1/6 Thus it is apparent that, when the magnet is displaced in a direction perpendicular to the attractive magnetic force, a restoring force comes into effect which is proportional to the rate of change d8 of the common area of the magnetic poles with respect to displacement dr. This restoring force is similarly effective with permanent magnets and electromagnets.

In the following description and in the claims the expression ring holder will be used in the interest of brevity to describe the support which maintains the ring in a floating condition, and it will be appreciated that when used in this sense the word holder does not imply any physical contact between the two elements.

FIG. 3 shows one embodiment of the present invention, in which a ring holder 2 has an inner ring-shaped air chamber 3. The ring holder 2 also has an annular surface with an L-shaped cross-sectional area, and has a cylindrically shaped inner surface 4 and a disc-shaped base surface 5. The ring 6 has an outer diameter which is slightly smaller than the inner diameter of ring holder 2, being maintained closely adjacent to, but spaced apart from ring holder 2. The left half of FIG. 3(a) shows a section taken along the line X X in FIG. 3(b), while the right half of FIG. 3(a) shows a section taken along the line Y Y in FIG. 3(b). Compressed air coming from one or more compressed air feed pipes 7 provided on the annular base 5 of the ring holder 2 passes through the air chamber 3 through nozzles 8, jetting out via a pressure chamber 9 to float the ring. The pressure chamber 9 is desirably a channel about 1 mm deep, and temporarily holds the jetted air to form a pressurized layer, and is useful for obtaining a stabilized floating force. Columnar permanent magnets I, 1' having the same cross-sectional areas are shown in this embodiment. They are disposed respectively at corresponding positions on the ring 6 and the ring holder 2 (both made of non-magnetic substances) and at a radius which is about the same as that of air nozzles 6. As is shown in FIG. 3(a), permanent magnets 1, l are mounted slightly recessed beneath the annular base of the ring holder. When air under controlled pressure is propelled from air nozzles 8, the ring 6 is stably and floatingly supported in space, without coming into contact with the ring holder 2. Yarn 10 passes through the gap 11 between ring 6 and ring holder 2, and is fed to a bobbin 13 supported and rotated by a spindle I2. The ring holder 2 reciprocates by means of a conventional drive means (not shown) along the bobbin 13 in an axial direction. The drive means may be a conventional cam mechanism or oil pressure mechanism, for example. The bobbin in this manner receives and collects the yarn to form a yarn package 14.

FIGS. 4(a) and (b) show another embodiment of the present invention. In this embodiment, in addition to ring 6 and ring holder 2, magnet holders 15, 15' composed of a non-magnetic substance are provided. Permanent magnets 1, 1' are disposed at corresponding positions of the ring and the ring holder along the circumference of the magnet holders at the same radius. The magnet holders and the permanent magnets are fitted at a distance (b) measured in the direction of the floating gap (a). At this time, when the ring 6 and the ring holder 2 are composed of a magnetic substance, such substance does not obstruct the action of the magnets or the effective operation of the winder.

In the aforesaid two embodiments, the magnets are fitted slightly recessed beneath the surfaces of the ring and the ring holder, which is an effective means for keeping the magnets out of the yarn path, facilitating floating of the ring when starting up, and in attaining the point of balance under the influence of air and magnetic forces.

Still another embodiment is shown in FIGS. 5(a) (d). In these embodiments, as shown roughly in FIG. 5(a), the magnets are annularly shaped electromagnets. On the outer walls of a ring 16 and a ring holder 17, apertures 18, 18' are provided. A magnetically attractive surface is provided in intermittent form around the circumference of each. Apertures 18, 18' are filled with a non-magnetic substance in a manner not to obstruct the winding-of the yarn. Further, as shown in FIGS. 5(b) and 5(c), the upper surface 19 of the holder, the bottom surface 20 of the ring and the outermost wall 21 of the holder are each composed ofa nonmagnetic substance. By applying an electric current to a coil 22 through wires carried in a pipe 23, an annular direct current electromagnet having an intermittently attractive surface is formed. Now, when compressed air is ejected from an air chamber 3 via nozzles 8, the bot tom surface 20 of the ring receives repulsive pressure and the ring floats in an amount corresponding to the pressure; however, as shown by the two dot-dash lines in FIG. 5(a), on account of the magnetic field brought about by applying the electric current, in the same manner as with the aforesaid two embodiments, a downwardly directed attractive force is imposed upon the ring and it tends to sink slightly. However, the position of the ring is limited by the balance between the magnetic force and the pneumatic force and defined in a radial direction by the attractive force of the magnet, moreover, because the magnetic attractive surface is provided intermittently, the motion in the circumferential direction is controlled. Therefore, the ring floats in a stable manner and is fixed in space without deviation or rotation. The outermost wall of the holder 21 further improves the stability of the ring in the radial direction by utilizing the pressure of discharged air by providing a gap formed between said outermost wall and the ring.

In the foregoing embodiments, magnets having mutual attractive forces are provided on the ring and/or the ring holder in a radial direction, because of which the ring does not rotate circumferentially.

In FIGS. 6(a) (0), still other embodiments of the present invention are shown. As shown in FIG. 6(a), the outer walls of ring 16 and of ring holder 17 are made of magnetically attractive surfaces which are continuous in their circumferential directions. This is accomplished by providing an annular direct current electromagnetic system. The action regulating the motion circumferentially of the ring disappears, therefore, the ring is free to rotate.

In all the embodiments previously described, the annular surface of the ring holder is generally L-shaped in cross-section, and ejects the fluid upwardly. At the same time, an attractive magnetic force is exerted axially of the ring holder. From the aforesaid principle of the present invention, it is also possible, as is shown in FIG. 7, to form the surface of the ring holder as a discshaped plane, and to support the ring with adequate stability.

However, since the ring tends to fall off when stopping or starting up, this arrangement is not practically preferable. And as in the aforesaid embodiments, when a side wall is provided for the ring holder, a pressurized fluid layer is formed also between the ring and the side wall,further improving the radial stability of the ring.

In the aforesaid embodiments, when the ring stands still, ,the frictional force between the ring and the yarn sliding around the outer periphery of the ring is relatively large. Accordingly, when the yarn is wound around the package at a certain winding tension, the permissible maximum denier, ballooning speed and number of twists are sometimes limited. However, when the ring is made freely rotatable, it whirls freely under the influence of the frictional force between the yarn and the outer periphery of the ring, reducing the relative frictional force between the ring and the yarn. At the same tension level the allowable number of turns of twist which can be applied to the yarn is greater when the ring is freely rotated.

Various combinations used in the present invention are schematically shown in FIG. 8, wherein the side of the ring and the side of the ring holder may extend either up or down. In FIG. 8, as shown in the legend, oblique line portions (c) represent magnets, dotted portions (d) represent non-magnetic substances and solid portions (e) represent magnetic substances. In the cases of combinations (a), (b), (d), (e) and (f) in FIG. 8, the ring rotates. In the cases of combinations (c) and (g), the ring is stationary.

A magnet having a continuous or intermittent attractive surface in the circumferential direction used in the present invention can, as shown in the aforesaid embodiments, be formed by the use of a columnar or annular permanent magnet or electromagnet.

A preferable dispostion of magnets when using permanent magnets, and without rotating the ring, is shown in FIG. 9. Specifically, when adjacent magnetic poles of permanent magnets 1, II are placed in mutually opposite positions, a magnetic substance 24 having the same radius as that at which the permanent magnets are disposed is provided on the upper surface of the permanent magnets on the ring side, and a similar magnetic substance 24 is provided on the bottom of the magnets on the holder side, a magnetic circuit as shown in the two dot-dash lines in FIG. 9 is formed. Because the resulting magnetic circuit becomes a closed loop, this is advantageous in that the efficiency of the permanent magnets increases and demagnetization decreases. This comment applies even when either one of these magnets 1, 1' is replaced by an electromagnetic substance.

FIGS. (a) (2) show simplified dispositions of magnets other than in free rotation of the ring. In FIG. 10(a), the ring holder 2 is a ring having spaced-apart inner and outer upstanding annular flanges. Columnar direct current electromagnets 25 are disposed at the same radius, and the polarities of the magnets are the same in an up and down direction. At this time, the magnetically attractive surfaces of the inner wall and the outer wall of the ring holder have the same polarity (North as shown). The ring member consists of two permanently magnetic annular flange rings 26, 26 corresponding in radial location to the attractive surfaces of the inner wall and the outer wall of the ring holder. The ring is preferably so constituted as to make these two rings integral by a means of non-magnetic substance material 29.

Further, FIG. 10(b) shows a case wherein, between the inner wall 2 and the outer wall 2" of the ring holder, in the radial direction of the ring holder leading to the center of the circle, a columnar direct current electromagnet 25 is disposed and the polarities of the magnet 25 are consolidated at the inner wall and the outer wall, and the inner wall and the outer wall of the holder have different polarities. At this time, ring 6 is preferably made of a permanently magnetic material.

Next, FIG. 10(c) shows a case wherein at the side of the ring holder, columnar direct current electromagnets 25 are disposed concentrically along the circumference of the ring holder at regular intervals. Ring 6 is composed of a magnetic material whose inner and outer diameters are the same as the diameters of imaginary circles circumscribed around the inner and outer extremities of the magnets. The shape of the attracting surface of the magnets may be circular, oval or rectangular. In FIGS. 10(0), (b) and (c), the columnar electromagnets may be made columnar electromagnets.

FIG. 10(d) is an embodiment showing the idea of mounting annular permanent magnets 27, 27 which are magnetized as that magnetic pole turns to axial direction on a ring and a ring holder. FIG. 10(e) is an embodiment wherein either one of the annular permanent magnets of FIG. 10(d) is replaced by a permanently magnetic substance 6 for purposes of simplification.

Other than the foregoing, various modes of practice are available in accordance with the basic combinations shown in FIG. 8.

In the present invention, when a slit is provided on a ring holder for passing the yarn, the yarn hooking operation toward the bobbin becomes very easy. FIG. 11 shows a basic form of such situation. When a slit is provided on the ring holder 2 for passing the yarn, in an annular electromagnetic system, the direction of the coil must be changed at the slit, and the ring holder for forming the magnetic circuit is divided into two parts.

FIGS. 12(a) and (b) represent embodiments of such case of an annular electromagnetic system. In this case, because the two pairs of holders are provided for forming the magnetic circuit in the ring holder, the ring is constituted by two permanently magnetic rings 26, 26' having different inner and outer diameters so as to correspond to each of the corresponding ring holders 2',

2" and an intervening nonmagnetic ring 29 joins these two rings together as shown in FIG. 12(b).

The principles by which a ring is stabilized in the foregoing embodiments is understood as follows. When compressed air is emitted as a jet from nozzles on the annular base of the inner surface of the ring holder, repulsion due to static and dynamic pressures of air is balanced with attractive magnetic force brought about by a magnetic circuit. Specifically, when forces exerted in an axial direction and a radial direction of the ring, effective upon the ring holder and the ring in the aforesaid embodiments of the present invention are diagrammatically shown, they operate in the manner shown in FIG. 13. Ring 6 is supported in space by the effects of a compression synthetic spring constant due to the total pneumatic pressure kz, an elongation spring constant due to attractive magnetic force kx and a synthetic decrement constant due to decrement by the entire pressure of compressed air between the ring and the ring holder and decrement brought about by difference in relative speed of the side wall of the ring from discharged air C2 in an axial direction; a compression synthetic spring constant by static pressure of air film brought about between the side wall of the ring and the side wall of the ring holder kr, an elongation systhetic spring constant by the centripetal force in a radial direction kr brought about by attractive magnetic force in an axial direction F2 and a synthetic decrement constant due to decrement by static pressure of air film brought about between the side wall of the ring and the side wall of the ring holder and due to decrement brought about by difference in speed of air emitted to the bottom surface of the ring and air emitted radially of the ring Cr, all in the radial direction of the ring.

In this system, the outer force working in an axial direction of a spindle is mainly periodic outer force Tz sin wt synchronized with the ballooning tension of the running filaments. Accordingly, the attractive force of the magnet is called Fz. At this time, it is assumed that motion in a horizontal (radial) direction and in an axial direction is not significant. When the rotating effect of a ring is neglected, the following equation is established as the equation of motion around a point of balance of the ring: t

Fz Az/( When the equation (4) is developed according to Taylors theorem, the linear portion is substituted in the equation (3) and the initial equilibrium is considered wherein ZAz/e corresponds to a spring constant Kz due to the magnet.

Toward the equation (l Routh Hurwitzs discrimination (cf A. HURWITZ, Uber die Bedingungen, unter welchen eine Gleichung nur Warleln mit negativen reelen Teilen besitzt, Mathematische Annular 46 (1895), 273 280) is applied, the following are the conditions under which this system becomes stable:

According to runs carried out according to the present invention, with reference to the ring of the present invention, the value of Cz is not very large. However, its.value is certainly positive by reason of the pneumatic pressure aroundthe ring. It is possible-to satisfy the conditions of the inequality (7) easily by adjusting the speed of emission of pressurized air, intensity of magnetism, weight of the ring and the spacing of the gap between thering holder and the ring. The experimental results with reference to this are shown in the graph, FIG. 1.

outer force is Tz sin wt 5 T2, the stability is limited.

In case decrement (decreasing) force CzZ 0, when the ring once starts anup and down swinging motion, that motion does not decrease. Actually, however, the decrement (decreasing) force exists and how it plays an important role is understood from the stable conditions of the inequality (6).

ln the embodiments of the present invention, with reference to the stability in the radial direction of the ring.'when, as mentioned above with reference to FIG.

2. from said equation (2), a change ratio of the com-.

mon area toward displacement is increased, it is seen that the restoring force is increased also. For that end, it is preferable in the embodiment of the present invention to make the attractive areas of magnets mounted on the ring and'the ring holder-equal (in case of annular magnets, the width of the attractive areas in a radial direction), moreover, to make the centers of the magnets common. Accordingly, in the embodiments in which discontinuous magnets are disposed, the number of the magnets is increased. In embodiments having continuous belt-like attractive areas, it suffices to'increase the number of steps of the belt-like magnetic poles.

In FIG. 1'4, the embodiment of an annular magnet is simplified and shown. T he magnetic attractive area 30 of ring holder} is provided in four steps in a radial direction and the ring is composed of four magnetic rings 26 having the same width as said attractive area, and non-magnetic rings 29 joining them together. It is seen from test runs that the force Fr is proportional to displacement r also.

When the equation of motion of arrangement is sought, to prove the stability in a radial direction of the ring by the same method as that of the aforesaid case of stability in an axial direction of a spindle, the resulting equation is:

m'f+ Crr'+ Krr Fr= Tr sin wt when the equation (2) is substituted therein;

'r'+ Cr/m 5+ l/m (Kr BMle dS/dr ra= Tr/m sin wt wherein r represents displacement of the ring from the point where the ring is balanced atthe central portion of the ring holder, Crr represents decrement (decreasing) force in a radial direction'brought about by relative speed to the ring due tofluid jet emissionin the radial direction, the -M represents synthetic magnetomotive force, B represents a proportional constant and.

BMIe dS/dr represents a spring constant in a radial direction caused by attractive force in an axial direction of the magnet Fz, and Tr represents the ampl'tude of the periodic outer force in a radial direction brought about when the filaments to be treated slidably contact the outer periohery of the ring.

As will be seen from FIG. 2, the common area S is:

El dxX4n accordingly, dS/dr -2nat wherein a represents the radius of the cross-sectional area of a columnar magnet, n represents number of said magnets. However, in the calculation of said dS/dr high degree terms are deleted as negligible. When this is substituted into equation (9):

wherein values of Cr and (Kr+ ZBMale) being positive, toward swing in the radial direction of the ring, in

' the vicinity of the point of balance, the ring does not vacillate but is always stable.

In order to increase the compression synthetic spring constant Kr due. to the static pressure of the air film created at the side wall of the ring holder and at the side surface of the ring, it is possible to emit an air jet from the side wall of the ring holder toward the side surface of the ring through nozzles 2' also as shown in FIG. 15. At this time, because the synthetic decrement constants Cr and Cz in the radial and axial directions of the ring brought about by the difference of speed of the surface of the ring from the emitted air, etc. increase the stability of the ring is further improved.

Accordingly, the yarn twisting apparatus of the presand axial direction. This is also proved theoretically as mentioned above. Accordingly, yarns can be conducted in the gap between the ring holder and the ring, and can carry out yarn twisting and winding in a stable manner without breakage of the twisted yarn.

In order further to explain this fact, reference is made to the graph appearing in FIG. 16. Actually measured values of spring constants in the axial and radial directions of the ring, are shown. The results were measured by using a 0.5 kg ring and 12 magnets having residual magnetism of 13,000 gauss, using an apparatus of the type shown in FIG. 3. On the ordinate of the graph, the spring constant in the axial direction [(2 e 2Az/3 (broken lines) and the spring constant in the radial direc tion Kr 2n a BMle (solid lines) are plotted. On the abscissa of said graph, the pressure P of emitted air is plotted. When the trend of FIG. 16 is stated, with reference to the spring constant in the radial direction, when magnets are not used, the value of the constant increases with elevation of pneumatic pressure. This is because the amount of discharged air entering the gap between the side wall of the ring holder and the side surface of the ring and the pressure of the air film at that portion increases. When using magnets, the spring constant in the radial direction further increases by the effect of the centripetal action of the magnets as compared with not using magnets.

The spring constant in the axial direction increases when using magnets as compared with not using magnets. When magnets are not used, even when the pneumatic pressure is elevated, said constant does not change greatly. However, when using magnets, said constant suddenly increases by elevation of the pneumatic pressure. This is considered because the amount of float of the ring decreases by the attractive effect of the magnets, the entire pneumatic pressure in the gap between the bottom surface of the ring and the annular base of the holder increases.

As mentioned above, when the ring of the present invention is used, it is not necessary at all to use a traveler for yarn twisting and winding which had hitherto been used. Therefore, not only is it possible to increase the yarn treating speed by several times, but also in respect of noise, swing and conservation, very large benefits are obtained.

The methods of supporting the ring in the embodiments mentioned so far are of a thrust type, from the viewpoint of the shape of the bearing. The basic principles of the present invention are applicable also to journal type bearings. Namely, when a ring is supported at a central portion of a ring holder by air and, at the same time, an attractive force due to magnetism is added in the opposite direction, the repulsion by fluid is balanced with the attractive force of magnetism in the radial direction of the ring. Therefore, a point of stability at which substantially no force is added to the ring is created. As a result, the stability in the radial direction of the ring is improved drastically. Further, in the axial direction of the ring, it is possible to support the ring stably by balancing the centripetal force in the axial direction Fz brought about by the attractive force in the radial direction of the magnet Fr with the weight of the ring.

FIG. 17 is an embodiment of such type, which is composed of a ring holder 2 having in its inside an air chamber 3 and a coil 22 for introducing a fluid, for example, pressurized air. The ring holder 2 has an oblong crosssectional area. A ring 6 made of magnetic material having an outer diameter slightly smaller thatn the inner diameter of said ring holder 2. The ring holder's inner wall 31 is cylindrical. On its circumference, air nozzles 8 are provided. Inside the ring holder, the coil 22 is wound in the circumferential direction. In FIG. 17, (e) is a magnetic material and (a') is a non-magnetic material. When an electric current is sent into the coil, a magnetic circuit is formed as shown by dot-dash lines in FIG. 18.

Inthis embodiment, the principle by which the ring is stabilized will be stated as follows.

When pressurized air is emitted from the air nozzles 8 and the inner side wall of the ring holder, repulsion due to the static pressure and dynamic pressure of air is balanced with attractive magnetic force brought about by a magnetic circuit. When force in the radial direction of the ring working on the ring holder 2 and the ring 6 is diagrammatically shown, its effect is shown in FIG. 19. The ring 6 is supported toward the ring holder by the effects of a compression synthetic spring constant Kr due to the entire pneumatic pressure, an elongation synthetic spring constant kr due to the attractive magnetic force and a synthetic decrement coefficient Cr brought about by difference in relative speed of the ring from surrounding atmosphere in the radial direction. The outer force mainly working on such system is periodic horizontal force Tr sin wt brought about by the slidably contacting rotation of filaments 10, in which Tr is the amplitude of divided force in the radial direction of the ring brought about by yarn tension, being the ballooning angle speed of the filaments.

Accordingly, when the attractive force of the magnets is designated Fr, and it is assumed that the motion in the horizontal direction and the axial direction of the ring is not achieved, as an equation of motion around the point of balance of the ring, the following equation is established.

wherein m is mass of the ring and x is an increment of displacment from the balanced position of the ring (center of the ring holder). In general, the attractive force of magnetic force Fr is; when the proportional constant is designated Ar and the gap between the ring and the ring holder is called 6; as follows:

Fr Ar/(e 2:)

When the equation l 2) is developed according to Taylors theorem, the linear part is substituted in the equation (I1) and initial equilibrium is considered;

mlr' Cr)? Krx 2Ar/e3 x Tr sin on wherein ZAr/e" corresponds to the constant kr due to attractive magnets. When Routh Hurwitzs discrimination is applied to the equation (13), the conditions under which this system becomes stable are as follows:

Cr O

Kr ZA r/ According to the experiments conducted by the present inventors, toward the ring of the present invention, the value of Cr is not so large, however, its sign is certainly positive. And it is possible easily to satisfy the conditions of the inequality (15) by adjusting the jet speed of pressurized air, the intensity of magnetism, the weight of the ring and the gap between the ring holder and the ring. The experimental result with reference to this is, as mentioned above, the graph shown in FIG. 1.

When the ring deviates from the point of stability (point of balance) and the gap 6 between the ring and the ring holder transfers in a direction of becoming smaller, x 0 and Kr ZAr/e to satisfy the conditions of the inequality (15), when a transfers in the direction of becoming larger, x 0. Therefore, the conditions of the inequality (15 will be similarly satisfied. The ring is always asymptotically stable in the vicinity of the point of balance. When a compulsory outer force exists, since the norm of the compulsory outerforce is Tr sin an Tr, the-stability is limited. At the time of rotation of the ring, the aforesaid conditions for stability are further reinforced by a gyro-effect.

In this embodiment, when the stability of the ring in the axial direction of the spindle is explained, as explained in FIG. 2, when the change ratio of the common area of the nagnetic attractive areas toward displacement is increased, an increase of the restoring force is brought about. For that end, it is conceivable to increase the number of steps of belt-like magnetic poles in the axial direction in this embodiment, as in the embodiment of FIG. 14. And, as mentioned above, it is known that the force F2 is proportional to the displacement 2.

Accordingly, as shown in FIG. 18, when an electric current is sent into coil'22, a magnetic circuit as shown by dot-dash lines is formed between ring holder 2 and ring 6, and when the ring 6 deviates in the axial direction, a restoring force is brought about according to the aforesaid principle.

In order to certify the stability in the axial direction of the ring'by the method of the aforesaid case of stability in the radial direction, when the equation of motion of this (system) is sought;

wherein z represents displacement of the ring from the point of balance of the weight of the ring and the magnetic force F2 in the axial direction, C22 is decrement (decreasing) force in the axial direction brought about by the frictional force due to jetting in the axial direction of the'fluid, M is synthetic magnetomotive force, B is a porportional constant and Tz is the amplitude of periodic outer force in the direction 2 brought about by the motion of the filaments treated.

Whereas, as will be apparent from FIG. 2, the common area S is S 2 1r r (h -z) when the outer diameter and the length in the axial direction are designated r and h, accordingly, dr/a'z 2 7T r, therefore, the equation (17) becomes as follows:

wherein the values of Cz and B are positive. Accordingly, the ring always becomes stable in the vicinity of the point of balance toward swing in the up and down direction of the ring.

As such, the yarn twisting apparatus of this embodiment is also certain in its support, and stability in the radial and axial directions of the ring is very good. Therefore, it is possible to fix the ring in completely space. And, as shown in FIG. 17, it is possible to twist and wind up the yarn through the gap between the ring holder and the ring.

Accordingly, there being no necessity at all to use a traveler for yarn twisting and winding, as has hitherto been the case, it is possible not only to increase the treatingspeed of the filaments by a factor of several times, but also very large benefits are obtained in respect of noise, swing and conservation. i

However, in this embodiment also, at the time of carrying out the yarn hooking operation, it must be carried out by removing the ring 6 from the ring holder 2. Therefore, the yarn hooking operation of continuously running filaments is somewhat difficult. 5

Therefore, it is preferable to provide a vertical slit at one point on the ring holder. By this expedient, yarn booking of continuously running filaments is easy to accomplish.

An example of winding a coil with a slit ring holder is shown in FIG. 20(a) (0). An annular electromamgnet is formed in two steps and a coil 22 is folded back at the slit portion. As a method of forming a holder 17 and a ring 6 of the annular electromagnet at this time,

examples shown in FIGS. 20(b) and (c) are provided. However, the embodiment shown in FIG. 20(6) is better in stability in the axial direction of the ring. In FIGS. 20(b) and (c), the inner wall of the holder 32 and outer case'34 are composed of a non-magnetic substance.

It is also possible to form an annular electromagnet having a slit by the method shown in FIG. 21(a) and (b). In these embodiments, a plurality of columnar electromagne'ts 25 is arranged toward the axial direction of the ring holder between the outer walls 17, 17' of the holder at the same pitch, the polarities of the respective magnets are rendered uniform up anddown. Therefore, between the outer walls 17 and 17' of the holder, a magnetic field is formed which is continuous in the circumferential direction.

In FIGS. 20 and 21, the inner wall of the holder 32 is non-magnetic and protrudes from the attractive surface of the end of the outer wall of the holder 17. By so doing, it is possible to facilitate formation of the point of stability in FIG. 1, similar to providing magnets "in concave states in the embodiments of FIG. 3 and FIG. 4;

Still another embodiment of the present invention is shown in FIG. 22. In the embodiment of FIG. 17, winding tension lowers because the ring rotates as the yarn is wound, and the yarn can be wound up with high degree of twist. However, when it is unnecessary to obtain high number of turns of twist, the ring may be caused to stand still. As is shown in FIG. 22, when the magnetic attractive surface 30 in the circumferential direction of a holder is made discontinuous and the magnetic surface e of the corresponding ring is arranged diseontinuously at the same pitch, as will be apparent from the aforesaid Roters equation, the ring stands still and is supported in space.

In the apparatus of this form also, in order to facilitate yarn hooking of continuous running filaments, it is preferable to provide a vertical slit in a part of the ring holder.

In the embodiment shown above, the magnetic attractive direction is the axial direction or the radial direction of the ring holder only. However, it is also possible to support the ring in a stable condition by forming an L-shaped annular surface on the ring holder, projecting air from the side wall and the annular base of the ring holder, at the same time, by applying negative force in the axial and radial directions of the ring holder.

It is, of course, possible to form the annular surface obliquely as shown in FIGS. 23(0) or (b), or to form the same as a curved surface, or to provide it in other shapes.

Of the yarn twisting apparatus of the present invention, with reference to an apparatus in which a ring freely rotates, it is possible to provide a hook 33 on a ring 6, as shown in FIG. 24, and carry out yarn twisting via this hook 33.

When a hook is provided as such, it is preferable to provide at least two hooks at regular intervals in order to balance the ring. By so doing, it is possible to use an alternate hook after the working hook has become abraded by friction with the yarn. Actually, it is possible to change hooks in sequence or in alternation. When all the hooks on the ring are abraded, they may be replaced, together with the ring.

Accordingly, the hook changing operations in a commercial operation can be carried out at one place. Therefore, the labor required for changing the ring and the hooks can be shortened to 1/8 l/3 the labor required for changing the traveler and changing the ring when using a conventional traveler system.

Again, the the present invention, when the radius of the ring becomes large and the weight of the ring increases, it is possible to provide supplemental air nozzles 8' and to support the thrust of the ring by compressed air, as shown in FIG. 25.

As still another embodiment, it is naturally possible to engage a traveler with a ring rotatably fixed in space by the apparatus of the present invention, and to carry out the yarn twisting and winding. In this case, because the ring per se does not contact an outer meterial for support in space, it is possible to rotate the ring per se at a speed which is about the same as the speed of rotation of the traveler by frictional force between the ring and the traveler. Accordingly, it is possible to make the difference in relative speed between the ring and the traveler almost zero. As a result, it becomes possible to reduce the extent of abrasion of the traveler drastically and greatly prolong the replacement cycle. Again, when the traveler is used, because there is no initial impact with a bobbin rotating at a high speed, it is possible to wind yarn around the bobbin and great benefit is obtained with the halfway yarn hooking system of the yarn twisting and winding apparatus.

On the rotating ring of the yarn twisting apparatus of the present invention, the inertia of the ring, resistance of air and ballooning tension function as a load, except for which no other force is effective.

Since the ring does not cross the field of magnetic flux by reason of its rotation only, no resistance is brought about by magnetic force. Accordingly, since the ring starts to regular driving, torque of F ['0 (I: intertia moment of the whole rotating ring) is effective upon the ring. However, when the ring is regularly driven, only a force maintaining rotation (namely, mainly energy loss due to air resistance) is required. Accordingly, it is possible to lower the tension of the filaments drastically during regular operation, i.e., it becomes possible to increase the number of turns of twist imparted to the yarn and to wind the yarn up at a high speed. When an ordinary magnetic material is used as a ring, this is preferable because production is simplified and the cost is low, and it is possible to use an annular permanent magnet. However, as shown in the aforesaid embodiment, when a coil is provided on the ring holder and the ring is composed of an ordinary magnetic material, adjustment of magnetic force is easy. Such a form is most preferable.

Of the yarn twisting apparatus of the present invention, in the case of an apparatus in which the ring rotates, upon stopping the ring rotating at a high speed, when the electric current running in the coil is left intact and supplying amount of air is decreased, the rotating ring stops almost instantaneously (in case of a 6,000 r.p.m. ring within 1 second). Therefore, this combination has very good operability.

Again, in the yarn twisting apparatus of the present invention, it is possible to control the r.p.m. of the ring by adjusting the inclination of the nozzles (the angle at which air is projected), the pneumatic pressure, the electric current running in the coil, and the weight of the rotating ring. It is possible to decrease the relative speed of the yarn to that of the ring, thereby lowering the winding tension. Increases of the number of twists, and improvement of yarn quality follow.

And because only air and magnetic force are used in the apparatus of the present invention, lubricants are not needed in some parts, and the apparatus avoids staining or burning by the lubricant of the traveler, and damage due to burning and injuries to personnel as a result of the traveler breaking or flying off.

The present invention is not limited to the embodiments as shown above, but various other embodiments are possible by combining a method of forming an annular surface of a ring holder with disposition of magnets as shown in FIG. 8.

Hereinbelow, the present invention will be explained in detail by reference to examples.

EXAMPLE 1 A yarn twisting apparatus, whose ring and ring holder have the shapes shown in FIG. 3, was used in winding a yarn around a bobbin.

The ring had an outer diaemter of 200 mm, an inner diameter of mm, a side wall height of 20 mm and a weight of 1.5 kg. The ring holder has an outer wall inner diameter (in which the ring was inserted) of 200.7 mm, and the height of its outer wall of 20 mm. The ring and the ring holder were made of brass, which is a non-magnetic substance. On the ring holder, 45 nozzles each having a diaemter of 0.7 mm were pro vided, through which air having an absolute pressure of 3 kg/cm was supplied. Six columnar permanent magnets each having residual magnetism of 13.0 KG (Gauss, unit of magnetic force), a diaemter of 7 mm and a length of 10 mm were provided on the ring and the ring holder, respectively so that they would attract each other.

Using said apparatus, a yarn was wound up around a bobbin at a yarn speed of 3,000 m/min., a spindle r.p.m. of 19,000 and a winding tension of 50 g. The ring did not contact the ring holder nor did it rotate, but it was stably supported in a floating condition and wound the yarn up in a stable condition. The wound yarn was twisted at a twist of 6.3 T/m.

EXAMPLE 2 A yarn twisting apparatus whose ring and ring holder had shapes shown in H6. 6 used in winding a yarn around a bobbin.

The ring had an outer diaemter of 133.0 mm and a height of 15 mm, and the ring holder had an outer wall inner diameter of 133.2 mm. The height of its outer wall was 15 mm. Magnets constituting portions of the ring holder and parts to be attracted of the ring were made of steel and the rest of both the ring holder and the ring were made of brass. 32 nozzles, each having a diameter of 0.7 mm were provided on the ring holder,

EXAMPLE 3 The same ring and ring holder as used in Example 1 were used. However, the magnets were not provided, but the ring was supported by floating by air only.

Using said apparatus, yarn was wound around a bobbin at a yarn speed of 600 m/min and a spindle r.p.m.

of 10,000. However, the ring began to whirl as the yarn speed increased, and when the speed of rotation of the ring reached about 500 rpm, the ring began to whirl eccentrically, impinged against the ring holder and the yarn broke. As a result, it was not possible to wind the yarn around the bobbin until it was fully loaded.

EXAMPLE 4 The same ring and ring holder as used in Example 1 were used. However, the magnets were not provided, and 45 nozzles each having a diameter of 0.7 mm were newly provided on the side wall of the ring holder through which air having an absolute pressure of 3 kg/cm was'supplied.

Using said apparatus, yarn was wound around a bobbin at a yarn speed of 600 m/min and a spindle r.p.m. of 10,000. However, when the rpm. of the ring reached 1,000 1,200, the ring began to whirl eccentrically, impinged against the side wall of the ring holder and yarn breakage took place. As a result, it was not possible to wind the yarn around the bobbin until it was fully loaded.

What is claimed is: y

l. A yarn twisting apparatus comprising, in combination:.

a. a spindle arranged to carry a bobbin for winding yarn,

b. a ring arranged for guiding said yarn to said bobbin, said ring substantially surrounding said spindle,

c. a ring holder also substantially surrounding said spindleand moving back and forth generally axially of said spindle, the ring holder including a fluid chamber, an annular surface for mounting said ring loosely, means for projecting compressed fluid through said annular surface from said fluid chamher, and

d. means for applying magnetic force by which said ring is attracted substantially toward said annular surface through which said compressed fluid is projected, so that said ring is supported in space in a stable condition balanced by the magnetic force and by the forces attributable to said compressed fluid.

2. An apparatus according to claim 1, wherein said annular surface of said ring holder is composed of an inner surface having a circular side wall and an annular base which has a concave L-shaped cross-section.

3. -An apparatus according to claim 2, wherein said fluid nozzles are provided on said annular base to emit compressed fluid axially of said ring holder, and an attractive magnetic force between said ring and said ring holder is excited in an axial direction of said ring holder.

4. An apparatus according to claim 2, wherein said fluid nozzles are provided on said inner surface of said circular side wall and said annular base to emit compressed fluid in axial and radial directions of said ring holder, and an attractive magnetic force between said ring and said ring holder is excited axially of said ring holder.

5. An apparatus acccording to claim 2, wherein said fluid nozzles are provided on said inner surface of said circular side wall and said annular base, and an attractive force between said ring and said ring holder is ex- I cited radially of said ring holder.

6. An apparatus according to claim 2, wherein said fluid nozzles are provided on said inner surface of said circular side wall and said annular base, and an attractive magnetic force between said ring and said ring holder is excited in both radial and axial directions of said ring holder.

7. An apparatus according to claim 1, wherein said annular surface of said ring holder is composed of a circular inside wall of said ring holder, and an attractive magnetic force between said ring and said ring holder is excited radially of said ring holder.

8. An apparatus according to claim 1, wherein said annular surface of said ring holder is composed of an annular upside plane of said ring holder, and an attractive magnetic force between said ring and said ring holder is excited axially of said ring holder.

9. An apparatus according to claim 1, wherein said annular surface of said ring holder is composed of an annular oblique upside plane.

10. An apparatus according to claim 1, wherein said means for exciting magnetic force includes magnetic attractive surfaces provided on both sides of said ring and said ring holder.

11. An apparatus according to claim 10, wherein both of said magnetic attractive surfaces are provided continuously along the circumferential direction.

12. An apparatus according to claim 10, wherein both of said magnetic attractive surfaces are provided intermittently along the circumferential direction.

13. An apparatus according to claim 12, wherein said means for exciting magnetic force consists ofa plurality of columnar permanent magnets, the magnetic poles of each magnet being arranged alternately in opposing directions, and wherein a surface of each magnet contacts a magnetic substance to bring forth a magnetic line of force in a closed loop from the opposite side magnet through the adjacent magnet.

14. An apparatus according to claim 10, wherein said magnetic attractive surfaces on both sides of said ring and said ring holder have substantially the same width.

15. An apparatus according to claim 10, wherein more than two rounds of said magnetic attractive surfaces are provided on both sides of said ring and said ring holder.

16. An apparatus according to claim 1, wherein said means for exciting magnetic force includes a magnetic attractive surface provided on either side of said ring or said ring holder, the other side being provided with a magnetic substance.

17. An apparatus according to claim 16, wherein said magnetic attractive surfaces and said magnetic substance are provided continuously in the circumferential direction.

18. An apparatus according to claim 16, wherein a plurality of said magnetic attractive surfaces are provided intermittently in the circumferential direction, and said magnetic substance is provided continuously in the circumferential direction.

19. An apparatus according to claim 16, wherein a plurality of said magnetic attractive surfaces and a plurality of said magnetic substances are provided intermittently in the circumferential direction.

20. An apparatus according to claim 16, wherein said magnetic attractive surfaces and said magnetic substancehave the same width.

21. An apparatus according to claim 16, wherein said means for exciting magnetic force consists of an annular electromagnet in which an electric current is sent along the circumferential direction in an annular holder of a magnetic substance in general U-formation in its cross-section and an opened portion of said annular electromagnet and said magnetic substance have the same width.

22. An apparatus according to claim 1, wherein said means for exciting magnetic force is provided directly on at least one of said ring and said ring holder.

23. An apparatus according to claim 1, wherein said means for exciting magnetic force is provided indirectly on at least one of said ring and said ring holder through a magnetic holder made of a non-magnetic material.

24. An apparatus according to claim 1, wherein said fluid nozzles have a pressure chamber on said annular surface of said ring holder.

25. An apparatus according to claim 1, wherein said means for exciting magnetic force is provided on at least one side of said ring and said ring holder in a slightly lower position from said annular surface.

26. An apparatus according to claim 1, wherein said apparatus includes more than two rounds of said magnetic attractive surfaces and said magnetic substance.

27. An apparatus according to claim 1, wherein said ring holder has a slit for said yarn.

28. An apparatus according to claim 1, wherein said ring is carried to rotate freely, and has a hook to guide said yarn.

29. An apparatus according to claim 28, wherein at least two of said hooks are provided.

30. An apparatus according to claim 1, wherein said ring is carried to rotate freely and has a traveler arranged to guide said yarn.

31. In an apparatus for winding yarn upon a package, means for feeding said yarn to said package comprismg:

a guide member disposed around said package, around which the incoming yarn is trained enroute to said package,

a spaced support for said guide member, which support is driven in reciprocation along the package,

said support including means projecting fluid at said guide member in a manner to generate fluid forces tending to separate said guide member from said support, and

magnetic means operative and effective between said guid member and said support developing magnetic attractive forces opposing said fluid forces. 

1. A yarn twisting apparatus comprising, in combination: a. a spindle arranged to carry a bobbin for winding yarn, b. a ring arranged for guiding said yarn to said bobbin, said ring substantially surrounding said spindle, c. a ring holder also substantially surrounding said spindle and moving back and forth generally axially of said spindle, the ring holder including a fluid chamber, an annular surface for mounting said ring loosely, means for projecting compressed fluid through said annular surface from said fluid chamber, and d. means for applying magnetic force by which said ring is attracted substantially toward said annular surface through which said compressed fluid is projected, so that said ring is supported in space in a stable condition balanced by the magnetic force and by the forces attributable to said compressed fluid.
 2. An apparatus according to claim 1, wherein said annular surface of said ring holder is composed of an inner surface having a circular side wall and an annular base which has a concave L-shaped cross-section.
 3. An apparatus according to claim 2, wherein said fluid nozzles are provided on said annular base to emit compressed fluid axially of said ring holder, and an attractive magnetic force between saiD ring and said ring holder is excited in an axial direction of said ring holder.
 4. An apparatus according to claim 2, wherein said fluid nozzles are provided on said inner surface of said circular side wall and said annular base to emit compressed fluid in axial and radial directions of said ring holder, and an attractive magnetic force between said ring and said ring holder is excited axially of said ring holder.
 5. An apparatus acccording to claim 2, wherein said fluid nozzles are provided on said inner surface of said circular side wall and said annular base, and an attractive force between said ring and said ring holder is excited radially of said ring holder.
 6. An apparatus according to claim 2, wherein said fluid nozzles are provided on said inner surface of said circular side wall and said annular base, and an attractive magnetic force between said ring and said ring holder is excited in both radial and axial directions of said ring holder.
 7. An apparatus according to claim 1, wherein said annular surface of said ring holder is composed of a circular inside wall of said ring holder, and an attractive magnetic force between said ring and said ring holder is excited radially of said ring holder.
 8. An apparatus according to claim 1, wherein said annular surface of said ring holder is composed of an annular upside plane of said ring holder, and an attractive magnetic force between said ring and said ring holder is excited axially of said ring holder.
 9. An apparatus according to claim 1, wherein said annular surface of said ring holder is composed of an annular oblique upside plane.
 10. An apparatus according to claim 1, wherein said means for exciting magnetic force includes magnetic attractive surfaces provided on both sides of said ring and said ring holder.
 11. An apparatus according to claim 10, wherein both of said magnetic attractive surfaces are provided continuously along the circumferential direction.
 12. An apparatus according to claim 10, wherein both of said magnetic attractive surfaces are provided intermittently along the circumferential direction.
 13. An apparatus according to claim 12, wherein said means for exciting magnetic force consists of a plurality of columnar permanent magnets, the magnetic poles of each magnet being arranged alternately in opposing directions, and wherein a surface of each magnet contacts a magnetic substance to bring forth a magnetic line of force in a closed loop from the opposite side magnet through the adjacent magnet.
 14. An apparatus according to claim 10, wherein said magnetic attractive surfaces on both sides of said ring and said ring holder have substantially the same width.
 15. An apparatus according to claim 10, wherein more than two rounds of said magnetic attractive surfaces are provided on both sides of said ring and said ring holder.
 16. An apparatus according to claim 1, wherein said means for exciting magnetic force includes a magnetic attractive surface provided on either side of said ring or said ring holder, the other side being provided with a magnetic substance.
 17. An apparatus according to claim 16, wherein said magnetic attractive surfaces and said magnetic substance are provided continuously in the circumferential direction.
 18. An apparatus according to claim 16, wherein a plurality of said magnetic attractive surfaces are provided intermittently in the circumferential direction, and said magnetic substance is provided continuously in the circumferential direction.
 19. An apparatus according to claim 16, wherein a plurality of said magnetic attractive surfaces and a plurality of said magnetic substances are provided intermittently in the circumferential direction.
 20. An apparatus according to claim 16, wherein said magnetic attractive surfaces and said magnetic substance have the same width.
 21. An apparatus according to claim 16, wherein said means for exciting magnetic force consists of an annular electromagnet in which an electric cuRrent is sent along the circumferential direction in an annular holder of a magnetic substance in general U-formation in its cross-section and an opened portion of said annular electromagnet and said magnetic substance have the same width.
 22. An apparatus according to claim 1, wherein said means for exciting magnetic force is provided directly on at least one of said ring and said ring holder.
 23. An apparatus according to claim 1, wherein said means for exciting magnetic force is provided indirectly on at least one of said ring and said ring holder through a magnetic holder made of a non-magnetic material.
 24. An apparatus according to claim 1, wherein said fluid nozzles have a pressure chamber on said annular surface of said ring holder.
 25. An apparatus according to claim 1, wherein said means for exciting magnetic force is provided on at least one side of said ring and said ring holder in a slightly lower position from said annular surface.
 26. An apparatus according to claim 1, wherein said apparatus includes more than two rounds of said magnetic attractive surfaces and said magnetic substance.
 27. An apparatus according to claim 1, wherein said ring holder has a slit for said yarn.
 28. An apparatus according to claim 1, wherein said ring is carried to rotate freely, and has a hook to guide said yarn.
 29. An apparatus according to claim 28, wherein at least two of said hooks are provided.
 30. An apparatus according to claim 1, wherein said ring is carried to rotate freely and has a traveler arranged to guide said yarn.
 31. In an apparatus for winding yarn upon a package, means for feeding said yarn to said package comprising: a guide member disposed around said package, around which the incoming yarn is trained enroute to said package, a spaced support for said guide member, which support is driven in reciprocation along the package, said support including means projecting fluid at said guide member in a manner to generate fluid forces tending to separate said guide member from said support, and magnetic means operative and effective between said guid member and said support developing magnetic attractive forces opposing said fluid forces. 